3.3 Teflon-Free Microvascular Decompression
By Richard Zimmerman, MD (USA neurosurgeon)
Dr. Peter Jannetta (USA) championed MVD as a treatment for TN sixty years ago. Through his tireless support and work to help the facial pain community, Dr. Jannetta also made this procedure a part of mainstream neurosurgery. In the initial descriptions of this procedure, the technique used to elevate a blood vessel off the trigeminal nerve was to insert a small piece of sterile felt under or against the vessel such that the compression was eliminated. The use of Teflon felt has been effective, as demonstrated by the successful results that Dr. Jannetta and many neurosurgeons have achieved. As MRI quality became more sophisticated and detailed, it became apparent that re-imaging patients with post-surgical pain recurrance showed a mass of Teflon against the trigeminal nerve. Could it be that, in these cases, the surgery only replaced vascular compression with Teflon compression or that the Teflon against the nerve still transmitted vascular pulsations? I decided that, in my surgical cases for TN, I would try to avoid using Teflon and instead simply relocate or transpose the position of the compressing blood vessel(s) away from the trigeminal nerve. To maintain the vessel in its transposed location, I used a biologic adhesive known as fibrin glue inside the brain that is commonly used in neurosurgery outside of the brain to aid in sealing off its covering, the dura. The goal of this technique was to completely remove anything whatsoever from touching the “sensitive” trigeminal nerve. Thus, I started performing “microvascular transpositions” (MVTs) or “Teflon-free MVDs.” I did not invent this approach. Other neurosurgeons have published their series of TN surgeries employing a “noncompressive” technique. Variations on the use of Teflon have been described. These include the use of other types of sponges, sutures, slings, and aneurysm clips. This is not to say that there is anything wrong with the use of Teflon. However, the pattern that I observed in postsurgical recurrences of pain typically involved Teflon seen against the trigeminal nerve on imaging.
After almost 20 years of using this technique consistently, I wanted to evaluate and compare the long-term results of this strategy for treating TN. Thus, I adopted the method of patient-reported outcomes and sent a questionnaire to my patients who had a Teflon-free MVD to learn about their surgical outcomes. I contacted 102 patients and received 85 responses. The ages of those responding ranged from 20 to 89 years. The duration of time after surgery ranged from 9 months to more than 17 years. Long-term, pain-free results were achieved in 89.4% of patients with a mean follow-up duration of 6.9 years. This is a rate of success that compares with the reported outcomes in the literature. I was also able to examine the outcomes divided into the patients who provided a description of intermittent attacks of facial pain alone (TN type 1) versus attacks of facial pain with a background component of constant pain (TN type 2). Although both groups did well, I found that TN type 1 patients did better, with nearly 93% of TN type 1 patients pain-free at 10 years. This study has limits, and they are outlined in the full article. The conclusion, however, is that Teflon is not necessary for a successful TN surgery. Achieving a good decompression whether or not Teflon is used is the goal of MVD surgery.
Patients should always feel comfortable discussing any plans for an operation with their surgeon, including the option of having a Teflon-free MVD. However, given the widespread and classic teaching of using Teflon, it is not likely that many neurosurgeons will be experienced treating TN with vascular transposition. One therefore must decide whether they want to ask their surgeon to perform a procedure with a technique they do not routinely use or find a surgeon who is familiar with this technical nuance.
Editor’s Note: Dr. Zimmerman, a longtime member of the American Facial Pain Association Medical Advisory Board, should be complimented on his effort to review the results of his innovative technique in the treatment of trigeminal neuropathic pain. His results are excellent and match the highest standard achieved by other distinguished neurosurgeons. Dr. Zimmerman asks reasonable questions: “Can Teflon cause trigeminal neuralgia?” and “Can Teflon continue to transmit pulsations from arteries and thus not adequately decompress the trigeminal nerve?” The unanswered question is whether Teflon itself has some intrinsic quality or leads to some undescribed reaction that can cause TN to recur. These inquiries remain to be answered through further studies like the one published by Dr. Zimmerman.
